In the circuit shown in the figure, $$V_A>V_B.$$ Which of the diodes conduct?

 1 only $$D_3$$ 2 $$D_1$$ and $$D_3$$ 3 all of the diodes 4 none of the diodes
Subtopic: Â PN junction |
Â 51%
From NCERT
Hints

The current-voltage characteristic of an ideal $$\mathrm{p \text{-}n}$$ junction diode is given by the graph as shown in the following figure:

This diode is connected with a resistance of $$5~\Omega$$ in series with it as shown below:

Which of the following shows the dependence of the voltage $$V_{AB}$$ and the current $$i$$, when the diode is forward-biased? ($$V_{AB}$$ in volt, $$i$$ in ampere)

 1 $$V_{A B}=i\cdot5+0.6$$ 2 $$V_{A B}=i\cdot5-0.6$$ 3 $$V_{A B}=i\cdot5+(0.6-5)$$ 4 $$V_{A B}=i\cdot5+\left(0.6+5\right)$$
Subtopic: Â PN junction |
From NCERT
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
To view explanation, please take trial in the course.
NEET 2025 - Target Batch

In the given circuits (a), (b) and (c), the potential drop across the two $${\mathrm{p\text-n}}$$ junctions are equal in:

 1 both circuits (a) and (c) 2 circuit (a) only 3 circuit (b) only 4 circuit (c) only
Subtopic: Â PN junction |
Â 65%
From NCERT
NEET - 2022
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
To view explanation, please take trial in the course.
NEET 2025 - Target Batch

The resistance between $$A$$ and $$B$$ is

 1 $$100~\Omega$$ if $$V_A>V_B$$ and $$200~\Omega$$ if $$V_AV_B$$ 3 $$100~\Omega$$ 4 $$200~\Omega$$
Subtopic: Â PN junction |
Â 76%
From NCERT
Hints

The circuit shown in figure is given an input signal $$V_i,$$ which varies with time and the corresponding output is $$V_o.$$ Then,

 1 $$V_o=V_i+E$$ 2 $$V_o=V_i-E$$ 3 $$V_o=V_i,$$  only when $$V_i>E$$ 4 $$V_o=V_i,$$ only when $$V_i Subtopic: Â PN junction | From NCERT Please attempt this question first. Hints Please attempt this question first. A \(\mathrm{p\text-n}$$ junction has an electric field of $$6\times 10^{5}$$ V/m in the junction and the junction width is $$500$$ nm. The height of the potential barrier is:
1. $$0.6$$ V
2. $$0.3$$ V
3. $$0.5$$ V
4. $$0.25$$ V
Subtopic: Â PN junction |
Â 91%
From NCERT
Hints

Assume that the threshold voltage of a diode is $$0.7$$ V, and the forward resistance is negligible.

The current through the circuit is:
1. $$40$$ mA
2. $$54$$ mA
3. $$33$$ mA
4. $$26$$ mA
Subtopic: Â PN junction |
Â 54%
From NCERT
Hints

In an unbiased $$\mathrm{p\text{-}n}$$ junction, holes diffuse from the $$\mathrm{p\text{-}}$$regions to $$\mathrm{n\text{-}}$$regions because of:
 1 the attraction of free electrons of the $$\mathrm{n\text{-}}$$region. 2 the higher hole concentration in the $$\mathrm{p\text{-}}$$region than that in the $$\mathrm{n\text{-}}$$region. 3 the higher concentration of electrons is in the $$\mathrm{p\text{-}}$$region than that in the $$\mathrm{n\text{-}}$$region. 4 the potential difference across the $$\mathrm{p\text{-}n}$$ junction.
Subtopic: Â PN junction |
Â 67%
From NCERT
NEET - 2013
Hints

The $$(V\text-I)$$ characteristic of a silicon diode is shown in the figure. The resistance of the diode at $$V_D=-10$$ V is:${\mathrm{}}_{}$

1. $$1\times10^7~\Omega~$$
2. $$2\times10^7~\Omega~$$
3. $$3\times10^7~\Omega~$$
4. $$4\times10^7~\Omega~$$

Subtopic: Â PN junction |
Â 80%
From NCERT
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints
To view explanation, please take trial in the course.
NEET 2025 - Target Batch

Why can't we take one slab of p-type semiconductor and physically join it to another slab of n-type semiconductor to get a p-n junction?

 1 the diffusion of majority charge carriers will not occur. 2 the junction will behave as a discontinuity for the flowing charge carriers. 3 the junction will behave as a continuity for the flowing charge carriers. 4 both (1) and (2).

Subtopic: Â PN junction |
Â 77%
To view explanation, please take trial in the course.
NEET 2025 - Target Batch
Hints